ST. PETERSBURG — After nearly 15 months of renovations, the Cathedral of St. Jude the Apostle will open its doors Thursday with a Mass and celebration expected to draw 1,500 people to the home church of the Diocese of St. Petersburg.

Catholics in the 432,000-member diocese, which runs from Pinellas to Citrus counties, have been eagerly waiting to see the final results of the $9.2 million upgrade to the building at 5815 5th Ave N, St. Petersburg.

“It’s an incredible dream come true,” said the Most Rev. Robert Lynch, bishop of the St. Petersburg Diocese. “It’s so different than what we started with ... a lot brighter and a lot more Florida-like.”

The project didn’t just replace the roof and modernize the building’s pews and stained glass. Workers knocked out walls and added more than 7,000 square feet to the now-palatial gathering place. The contractor, Herman Construction Services of St. Petersburg, opened up the large rotunda above the altar and replaced four columns that held up the ceiling with four massive steel beams from Belgium - the biggest steel shipment to pass through the Port of Tampa in 33 years.

The renovation replaced what was nondescript tile flooring with sparkling, ivory-toned porcelain and green marble tiles. Workers installed a new baptismal fountain to the left of the pews that’s big enough for adult converts.

Art pieces from Italy now line the church, and a massive stained glass window by artist David Wilson looks to the east beyond the altar. Aloft and to the right of the sanctuary, a high-tech booth controls sound during services as well as on radio broadcasts. An aromatic, cedar-lined closet will hold the vestments of visiting clergy. Outside, a row of manicured date palms lines the sidewalk.

A new, 20-foot-tall cross now sits atop the dome.

The original cathedral, built in 1963, was not initially intended to be a spiritual center but became that in 1968, when the Diocese of St. Petersburg formed.

“So, for the first time, in a lot of ways, the diocese has a cathedral that’s really a cathedral — one that has a grandeur and an elegance,” said the Rev. Joseph Waters, director of the cathedral.

Those who led the project say that grandeur is merited and that the institution would not be spending such a large sum on the cathedral if it hadn’t already made gains in its efforts to help the poor. The project was paid for through a trust fund created with proceeds from the sale of vacant diocese land.

“There is always going to be a need in our diocese, and we truly, truly answer that need through Catholic Charities,” said Maureen Ahern, who co-chaired the project’s steering committee. “No other organization does what we do when it comes to helping the poor.”

The expanded church will help St. Jude’s better fulfill its role as the heart of the diocese. As the “mother” of the diocese, the cathedral is where all diocese-wide events take place, including local ordinations of priests and deacons. The parish itself services between 3,000 and 5,000 each week with masses, weddings, funerals and Sunday service.

Thursday’s events will feature clergy from across the county, including a bishop from Wyoming, the archbishop of Miami and Pope Francis’ diplomatic representative in Washington, D.C.

People attending the Mass must have a ticket, which have all been distributed. People can watch the service live online at www.dosp.org.